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volcanic rock

volcanic rock

4 3.6
A hard rock made when hot melted rock cools on or near the Earth's surface
  • noun
  • /vɑlˈkænɪk rɑk/
  • Specialized
translation icon : roca volcánica
  • The island of Rapa Nui was formed from volcanic rock millions of years ago.

Well, perlite is an expanded volcanic rock that is really, really lightweight.

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Examples

  • In truth, the effect is caused by gas escaping from volcanic rocks on the sea floor.

    Blog text (7)
  • It's actually a volcanic rock that's been expanded and it crushes very easily.

  • Now volcanic rocks in particular form like this one here, this is a volcanic rock.

  • We are looking at a steep cliff face composed of black volcanic rock.

    Fiction book (1993)
  • The structure was embedded partially in ice and volcanic rock, which helped to preserve it.

    Blog text (24)
  • There's a lot of volcanic rock and this rock actually is buildable material as well.

  • The porous volcanic rock results in a lack of perennial streams, but springs are present on the lower slopes of the volcanoes.

    Academic text (2004)
  • You've got these volcanic rock formations where there's all these crevasses, crevasse and tunnels.

  • Although forever marked with patches of sun-struck sagebrush and dark outcroppings of volcanic rock, Ravensfield Valley in June was as green and glorious as it would ever be.

    Fiction book (1993)
  • Iceland, which is itself a mass of volcanic rock erupted from the submarine meeting point of the North American and Eurasian tectonic plates, was effectively split apart.

    Academic text (2010)

Synonyms

obsidian
vsvolcanic rock
12 7.9

A hard dark rock made when lava cools quickly and becomes like glass with a smooth shiny surface

is the broader igneous class that includes both glassy and crystalline forms
basalt
vsvolcanic rock
  • Specialized
8 7.2

A dark, heavy rock made when lava cools

is the broad igneous category that covers all lava-formed rocks
volcanic glass
vsvolcanic rock
  • Specialized
1 6.7

A hard shiny rock made when hot lava cools and hardens very fast

is the igneous category that also includes slowly cooled crystalline rocks
rhyolite
vsvolcanic rock
  • Specialized
1 9.9

A light-coloured volcanic rock made when thick lava cools quickly and forms tiny crystals

is the general igneous type not limited to high silica compositions
andesite
vsvolcanic rock
  • Specialized
9.9

A dark volcanic rock made from lava near volcanoes

is the broad igneous class that includes many compositions
dacite
vsvolcanic rock
  • Specialized
9.9

A grey volcanic rock with many small crystals

is the general igneous group not limited to those specific minerals
tachylite
vsvolcanic rock
  • Specialized
9.9

A dark, glassy volcanic rock that forms when hot lava cools very fast

is the broad igneous category not limited to dark basaltic glass
peperino
vsvolcanic rock
  • Specialized
9.9

A rock made from volcanic ash and small pieces of lava used for building

is the general igneous type not focused on fragmental building stone
pillow lava
vsvolcanic rock
  • Specialized
7.0

Lava that hardens into rounded, pillow-like masses after erupting under the sea

is the igneous product formed at or near the surface, not only underwater

How Plutonic

plutonic rock
  • Specialized
8.7
volcanic rock
  • Specialized
4 3.6

Surface Forms

volcanic rock singular

Morphology

volcanic + rock

The meaning is directly and compositionally derived from 'volcanic' (related to volcanoes, lava or ash) + 'rock' (natural solid mineral material), so a learner who knows both words can infer it refers to rock formed by volcanic activity. This is a common, cross-linguistically consistent noun phrase following standard English adjective + noun composition, making it immediately comprehensible to B1 learners.

Etymology

Volcanic rock comes from a simple picture: when a volcano erupts, very hot melted rock called lava cools and hardens into solid rock, so the word volcanic, meaning 'from a volcano', plus rock describes that stone. That's why 'volcanic rock' means 'rock made from lava'.